docs: def fill_signed_info(self, signed_info):
          """
          Fills the SignedInfo node
          :param signed_info: SignedInfo node
          :type signed_info: lxml.etree.Element
          :return: None
          """
          for reference in signed_info.findall(
                  'ds:Reference', namespaces=constants.NS_MAP
          ):
              self.calculate_reference(reference, True)